Bastion Classification of Lower Limb Blast Injuries

Why Use

Developed to be a classification system that more comprehensively describes injury pattern of lower extremities after blast injuries. Correlates with treatment need, such as requirement for operative proximal vascular control or amputation level. Helpful in facilitating communication between clinicians and for operative management. Other scores for lower extremity injury severity such as the MESS may not be predictive of functional recovery after limb reconstruction ( Ly 2008 ), though we are not aware of any head-to-head comparison studies including the Bastion Classification.

When to Use

Patients with lower extremity injuries after explosions resulting in complex blast wounds. The constellation of injuries may include blunt or crush injuries, traumatic amputations, and compartment syndrome, as well as associated neurologic, thoracic, gastrointestinal, and genitourinary injuries.

Formula

Pearls / Pitfalls

The validation study of the Bastion Classification ( Jacobs 2014 ) was not designed to correlate class of injury with outcomes such as mortality, transfusion requirements, or definitive amputation level. Correlates better in blast injuries resulting in traumatic amputations than in segmental injuries. Because not all injuries involve complete traumatic amputation of a limb, this classification is supplemented by the suffix “S” to denote a segmental injury, defined as the presence of potentially viable tissue distal to the most proximal injury. Associated injuries to the intraperitoneal abdomen, genitalia and perineum, pelvic ring, and upper limbs are important in treatment and operative planning, so these are denoted by additional suffixes A-D, respectively. Prehospital application of a tourniquet can effectively obtain hemorrhage control. The study validating the Bastion Classification ( Jacobs 2014 ) had 98 injuries out of 179 (55%) requiring pneumatic tourniquets. A recent study in 2017 by Scerbo et al reports patients who presented without prehospital tourniquets received more transfusions in the first hour of arrival (55% vs 34%, p = 0.02) and had increased mortality from hemorrhagic shock (14% vs 3.0%, p = 0.01).

Management

Management depends on the injuries diagnosed. Using the Bastion Classification and suffixes, emergency physicians and trauma surgeons can anticipate the need for additional surgical consultations and the resources required for treatment.

More Information

Class Recommendation Initial debridement and/or amputation Method of vascular control 1 Debridement ± plaster of paris (PoP) splintage None required 1S PoP splintage ± debridement At most, tourniquet application 2 Most likely low or high transtibial amputation Tourniquet at any level; 1 had intraperitoneal iliac vessel control 2S Combination of debridement, PoP splintage, and external-fixation At most, tourniquet application 3 Most likely through-knee or low transfemoral amputation Tourniquet; may require intra- or less commonly extra-peritoneal vessel control 3S Majority required debridement only; also included PoP splintage, external-fixation, or low transfemoral amputation Tourniquet at any level; may require extra- or intra-peritoneal iliac vessel control 4 Most likely high transfemoral amputation Intra-peritoneal iliac vessel control; less likely extra-peritoneal control 4S Majority required debridement only; also included high transtibial or transfemoral amputation Tourniquet, femoral vessel or intra-peritoneal iliac vessel control 5 Most likely high transfemoral amputation Intra-peritoneal iliac vessel control; less likely extra-peritoneal control or tourniquet 5S Debridement only Extra-peritoneal vessel control Based on data from Jacobs 2014 .